U2251 Diagnostic Trouble Code

U2251 is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a U2251 diagnostic trouble code may include:

The engine oil will exhibit dilution from the ECUs attempts to increase engine temperature. Some vehicles advance the fuel injection timing slightly after top center to afterburn a small amount of fuel to increase exhaust temperatures. Some of this fuel enters the crankcase. When the ECU determines the necessity to regenerate the DPF, the service life of the oil be shortened significantly
Faulty or damaged wiring
Hesitation upon acceleration
Diminished fuel efficiency

Possible Causes :

The Mass Airflow sensor is a hot wire that senses the volume of air entering the intake manifold. The computer uses this information to control fuel mixture.
Defective ECU strategies or components will prevent proper regeneration
Fuel with a large percentage of sulfur will clog the DPF quickly

Repair Processes :

Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. Check to make sure they are not burnt or corroded. If in doubt, get some Electrical Contact cleaner at any parts store if cleaning of the terminals is needed.

Process Tips

Diagnostic trouble code U2251 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before U2251.

Fortunately, U2251 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U2251 Trouble Code For Specific Cars

U2251 Dkw 600 Idle Air Control System At Adaptive Clip
U2251 Lotus Elise 111r Traction Control Disable Lamp - Circuit Short to Battery
U2251 Bristol 402 Cooling Fan Driver Fault
U2251 Gaz 24-10 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1)
U2251 Mini 1000 Anti Theft System
U2251 Mercedes-benz W136 Air Suspension LF Air Spring Solenoid Output Circuit Short To Ground
U2251 Chevrolet Trans Sport Enable Signal Open Circuit